LIFTCALC is an EXCEL spreadsheet that was created to assist individuals that are involved with planning maintenance activities that will require rigging and lifting of equipment. It is NOT intended to superceed any equipment manufacturers instructions, plant procedures, or regulatory requirements. It is NOT replace sound engineering evaluations and calculations. All calculations must be verified by a qualified person.
Takeaway: . All calculations must be verified by a qualified person, final approval and decision forr use of any rigging is the responsibility of the qulified person.
The single most important rigging precaution is to determine the weight of a load before attem making ample allowances for unknown factors, and determining the available capacity of the equipment being used. It is equally important to rig the load so that it is stable, and the center of gravity is below the hook.The safety of personnel involved in rigging and hoisting operations largely depends upon care and common sense.
Remember these safe practices:
1.) Know the working load limit (WLL) of the equipment being used. NEVER exceed this limit.
2.) Determine the load weight before selecting rigging equipment. Don’t attempt to lift a load that has undetermined weight.
3.) The WLL of all rigging equipment appies only to freely-suspended loads on plumb hoist line.
4.) Sharp bends with slings must be avoided. Corner pads or softeners shall always be used.
BASIC VOLUME and WEIGHTS
This section performs simple computations on some typical shapes, and provides a list of materials to choose the corresponding weight for.
ESTIMATING WEIGHTS OF EQUIPMENT
This section will provide an “ESTIMATE” of equipment. The manufacturer should always be consulted for the exact weight, but if this is not possible then this calculation will provide a weight that is conservatively”HIGH”for safety considerations.
RATED CAPACITY OF RIGGING COMPONENTS
The WLL listed have been taken from OSHA, ANSI B30.9 and manufacturers ratings. They are assumed correct, but always check the ratings listed on the actual equipment whenever possible.
SLING ANGLES and REDUCTION in SWL‘s.
This whole topic is probably the most misunderstood area of safe rigging and hoisting. Rigging equipment is rated for VERTICAL lifting, whenever any angles are involved the WLL of the equipment is reduced the situations in the tension sections should, if nothing else, make the user aware of the inherent DANGERS involved with angular Rigging